Hypothesis

I believe that using bi-convex lenses, which concentrate a beam of light, will improve the efficiency of a solar panel.

Independent variables

Lenses used on solar panels

Dependent variables

Amount of voltage, current, and resistance

Controls

Time of tests

Angle of solar panels

Measurement tools

Experimental groups

One 12-volt (v) solar panel with three bi-convex lenses connected in a clockwise pattern on three sides of the test solar panel

Control groups

One 12v solar panel

Materials

Sunlight

Three bi-convex lenses, measuring 5 cm in diameter

Two 12v/15.24 cm x 17.78 cm x 2.54 cm solar panels

Two built-in blocking diodes for solar panels

Two 220-ohm resistors

Two 60.96 cm x 60.96 cm x 0.7 cm wooden boards

Two Radio Shack digital multimeters (voltage/ohmmeters)

Three 68-cm wire hangers

Three lens holders

Four 357A 1.5 v button-cell batteries

500-cm tape ruler, 30.5-cm ruler, and protractor

Solar calculator

Connectors

Brackets

Adhesives

Tape

Marker

Tools

Procedures

1. Set up experimental and control groups.

2. Place both groups outside at 8:50 a.m., when the sun's rays are striking the groups' location, at optimal angles to the sun.

3. For both groups, record the amount of voltages, without the resistors attached.

4. For both groups, remove the test leads and reset each voltage/ohmmeter.

5. For each solar panel, make contact between red and black test lead with the end wires of the 220-ohm resistor.

6. Record amount of resistance (in ohms) for both groups.

7. Take both groups indoors at 3:26 p.m., when the sun's rays are still strongly contacting with the solar panels and the bi-convex lenses.

8. Measure and record voltage, resistance, and current from each group; round the current and the voltage of each solar panel with the internal and external resistance to the nearest hundredths place.

9. Repeat experiment for the next two weeks, adjusting the times that the experimental and control groups are set out, after calculating the time for optimal sunlight.

Results

Table 1 shows the average volts and milliamps for each test.

Table 1: Average Volts and Milliamps for Each Solar Panel

Control Group

Test Group

Volts

Milliamps

Volts

Milliamps

Test 1

16.14286

5.85714

15.42857

5.15714

Test 2

17.00000

18.80000

16.85714

13.38571

Test 3

17.14286

31.84286

17.42857

20.51429

Conclusions

My hypothesis was that solar panels using bi-convex lenses are more efficient than standard solar panels. My hypothesis was incorrect, because the experimental group with the bi-convex lenses actually reduced the amount of milliamps, voltages, and current that the solar panel received.

A future experiment would use mirrors in front of the solar panel rather than bi-convex lenses, which would increase the amount of sunlight coming into contact with the photovoltaic cells.